The Compressed Bergen Overview
2NT shows a 4-card support raise with a wide range of HCP
Not a preemptive raise (<6 HCP), we use the double raise to the 3-level to show very weak hands, but with good trump support. This facilitates that the law of total trump (9) should play best at the 3-level. Both as a probably making contract and to do our best to shut out the opponents from bidding. When we have a 9 card fit, it is likely that the opponents have one as well.
You probably play (or are familar) with Jacoby 2NT (Game Force values and 4 card support raise) and Bergen Raises (4 card raise with 8-9 HCP and 4 card raise with 10-12 HCP). These Bergen raises are typically 3♣ and 3♦ and which is weaker is per partnership agreement.
We decided in our modern approach that we could compress these three bids into a single response: 2NT.
2NT shows 4-card support for the opening major suit and more than a preemptive, weak hand. A wide range. The 2NT is a question bid back to the opener. It asks them the quality of their opening hand. To rate the quality, we ask the opener to calcluate the Losing Trick Count of their and and bid at the 3-level to show that result.
- 3
- 5 LTC (aka a strong hand) - 3
- 6 LTC (aka a pretty good hand) - 3 of the bid Major - 7 LTC (minimal opening hand)
- 3 of the other Major - 4 LTC (aka a great hand, just short of opening with a strong 2 bid)
Why is this better than Jacoby+Bergen Raises
Those systems do work for most pairs. We have found the more exactly communication of the LTC strength of the opening hand leads us to more game contracts when the Bergen bidders have to make a guess. We reach more secure slam contracts and when the LTC calculation shows that we can safely play at the 5-level, we have options to explore for those slams that most pairs fail to find (or even consider)
Also, we free up the 3♣ and 3♦ bids for other purposes. Your partnership can use them as bids for invitational hands and a 6 card minor. In Modern American, we use them for a SPLimit (or KRaise) raise (invitational raise, 3 card support, and unspecified short-splinter-suit). We use the 3♦ response to show exactly a 4333 shape hand, 3 card support and game values. This is typically, 3NT in standard bidding. 3♦ gives use some room for exploration when the opener has extra values.